1. Field of the Disclosure
The technology of the disclosure relates to systems and methods for monitoring cooling systems in a distributed antenna system.
2. Technical Background
Wireless communication is rapidly growing, with increasing demands for high-speed mobile data communication. As an example, so-called “wireless fidelity” or “WiFi” systems and wireless local area networks (WLANs) are being deployed in many different types of areas (e.g., coffee shops, airports, libraries, etc.). Distributed communications or antenna systems communicate with wireless devices called “clients,” which must reside within the wireless range or “cell coverage area” in order to communicate with an access point device.
One approach to deploying a distributed antenna system involves the use of radio frequency (RF) antenna coverage areas, also referred to as “antenna coverage areas.” Antenna coverage areas can have a radius in the range from a few meters up to twenty meters as an example. One type of distributed antenna system for creating antenna coverage areas, called “Radio-over-Fiber” or “RoF,” utilizes RF communications signals sent over optical fibers. Both types of systems can include head-end equipment coupled to a plurality of remote antenna units (RAUs) that each provides antenna coverage areas. The RAUs can each include RF transceivers coupled to an antenna to transmit RF communications signals wirelessly, wherein the RAUs are coupled to the head-end equipment via the communication medium. The RAUs contain power-consuming components, such as the RF transceiver, to transmit and receive RF communications signals and thus require power to operate. Power may be provided to the RAUs from remote power supplies, such as at an IDF (intermediate distribution frame), or interconnect unit (ICU) closet at each floor of the building infrastructure.
Power supplies generate considerable heat, and often fans are used to dissipate the heat generated during operation of the distributed antenna system. However, as cooling fans continue to run, the drag on the fan motor will increase over time. This drag typically results from increased friction in the fan's motor bearings resulting from the limited life of the bearing lubrication. The drag can also be caused by an increase in the fan's static pressure, such as when debris accumulates in the fan filter. As fan drag increases, the fan's controller increases the current to the fan motor to ensure that the fan blades maintain a constant rate of revolution.
No admission is made that any reference cited herein constitutes prior art. Applicant reserves the right to challenge the accuracy and pertinency of any cited documents.